Company call centers or Internet-based support forums, also referred to herein as contact centers, put customers in contact with company agents (e.g. people working for the company providing customer service or other information to customers) for assistance. Agents' performance may be improved by increasing the agents' training. Agents may be trained for example, using coaching packages including training material which may be automatically distributed to agents, or in other manners. Typically, when a coaching package is launched or executed, agents are evaluated short time after the training material was sent to the agents, to test that the content of the coaching package is clear and after a predetermined time, e.g., after few weeks or months to see if the content is memorable. However, validating and testing that agents are adhering to the training material typically involves evaluating a real interaction with a real customer or with a human supervisor impersonating customer. This imposes a challenge on call centers operators, since in both cases highly trained supervisors are required for listening to calls with customers or for conducting validations sessions. The burden is significant also due to the need to constantly train new agents due to low job retention time.